Cylinder dampener for offsetprinting machines



March 25, 1952 M RAS 2,590,429

CYLINDER DAMPENER FOR OFFSET-PRINTING MACHINES Filed June 9, 1950 FIG.2

AINVENTOR: f /27/92( FMS 57- www@ uw@ #wm ,Wm/bals Patented Mar. 25, 1952 OFFICE CYLINDER DAMPENER FOR OFFSET- PRINTING MACHINES Max Ras, Zurich, Switzerland Application June 9, 1950, Serial No. 167,042 In Switzerland March 20, 1950 4 Claims.

Dampeners for producing jets of moist air for damping the cylinders on offset-printing machines are known in the printing art. A known dampener comprises an elongated box having an open top in form of a longitudinal slot and aircompressor means for producing a stream of air by means of which water atomized in the said box is delivered through the said slot to a portion of the offset printing machine.

In operation, a certain excess pressure is produced in the said box of such known dampeners, which pressure may give origin to leakage losses.

The dampener of my present invention com prises an atomizer box having an open top in form of a longitudinal slot and being subdivided into two chambers by means of a partition of which the top edge projects into the range of said slot. One of said chambers comprises means for atomizing water and at least one air-intake opening. The other chamber communicates with suction means for producing an air stream in the said box in order to discharge the nnely atomized and uniformly distributed water through the said slot to a portion of the offset machine.

In operation, therefore a subatmospheric pressure prevails in the said box of my present dampener, which pressure prevents the stream of moist air from leaving the box.

One form of invention is shown in the accompanying drawing in which- Fig. l is a cross-section, and Fig. 2 an elevation of one end portion.

The numerals I and 2 designate the damping rollers and 3 the atomizer box of the dampingapparatus. The box 3 is provided with an open top in form of a slot 4 of which the length is at least equal to that of the roller I. The said box is subdivided into two compartments 6 and I by means of a partition of which the tcp edge projects into the range of the slot 4. In the bottom of the chamber Ian opening 8 is provided, below which a drip vessel 9 is secured to the box 3. In the side wall of the box 3 dening the compartment 1, slots I0 are provided, which slots serve as air-intake openings. As shown in Fig. 2, a water conduit I2 provided with a pressure reducing valve II is connected to the bottom portion of box 3 and communicates with a distributing header I3 which extends through the entire length of the compartment ,'I. The header I3 on top is provided with discharge nozzles I4 which are directed toward a bale I5. The lower portion of the chamber 6 opens to a suction funnel I6 which communilOl- 147) Cates with an induced-draft blower II which exhausts into the atmosphere. As is shown in Fig. 1, the distance between the chamfered top edge I8 of partition 5 and the roller I is somewhat, e. g. from 1 to ll/z millimeters, greater than the distance between the edges of the slot 4 and the said roller.

The mode of operation of the dampener described otherwise is as follows: The water supplied through the conduit I2 to the distributing header I3, the flow of which may be regulated by means of the reducing valve II, is sprayed through the nozzles I4 in ne jets against the baille I5 and atomized thereby. Any drops of non-atomized water are precipitated on the wall dening the compartment 1 or on the partition 5, and may run 01T through the drain 8 into the vessel 9. At the same time, the blower I1 sucks air through the slots I0 and the compartments E and 1, the ow of air being indicated by arrows. The atomized water is carried forward by the air stream in form of a jet of moist air and, owing to its kinetic energy, is thrown through .the slot 4 onto the roller I.

The water pressure and, thus, the moisture content of the jet of moist air may be regulated by means ofthe pressure-reducing valve Il. It further is to be noted that the water is atomized solely through the impact of the water jets on the baffle I5, and that the air stream serves exclusively for the transport of the atomized water. In contra-distinction to damping-apparatus known in the art, compressed-air lines for producing an air stream are not required in my present invention.

The water may be atomized through atomizer nozzles or other known means, instead of in the manner described.

What I claim as new and desire to secure by Letters Patent is:

l. A cylinder damping apparatus for offset printing machines, comprising an atomizer box having an open top in the form of a longitudinal slot, a damping cylinder closely positioned above said slot and extending therealong, a partition wall projecting into the range of said slot and subdividing said box into two compartments, the top edge of said wall being spaced from said cylinder a distance slightly greater than the distance between the edges of the box walls forming the longitudinal slot and said cylinder, means for atomizing water in one of said compartments, an air entrance opening in said one compartn ment, suction means connected to the other said compartment, said suction means producing an air stream through said box over said top edge of said Wall and carrying therewith the atomized water in a uniformly distributed condition through the said slot and onto said cylinder for the damping thereof.

2. A damping apparatus as claimed in claim 1, in which the s aidsuction means comprise an induced-draft blower only.

3. A damping apparatus as claimed in claim 1,

in which a drip vessel is secured to the bottom l of the compartment containing said means for atomizing Water, said vessel communicating -with the said compartment through an openinginthe said bottom.

4. A damping apparatus as claimed in claim l, said partition Wall being straight Yand .having-a 4 tapered top edge on the side thereof facing said compartment having said means for atomizing Water therein.

MAX RAS.

REFERENCES CITED Theiollowing references are of record in the file-ofthis patent:

UNITED STATES PATENTS -`Number Name Date i2,108;9.84 Grembeck Feb. 22, 1938 2,178,583 Grembecki Nov. 7, 1939 .2,196,412 Grembecki Apr. 9, 1940 15 .2,824,787 Lundgren July 20, 1943 

